A communication system may include portable/mobile communication devices that are configured to transmit information directly to each other or through fixed network equipment (FNE), such as a base station 106. The portable/mobile communication devices may be radios, for example, portable two-way radios, mobile radios, or other similar portable or mobile voice communication devices. The radios may operate within a geographic area that has a virtual perimeter or virtual boundary (referred to herein as a geo-fence).
Radios facilitate communications between operating users by transmitting and receiving information on a group of pre-assigned frequency channels. When a radio enters or exits a geographic area defined by a geo-fence, the radio may perform operations associated with entering or exiting the geo-fence. For instance, when a radio enters or exits a geo-fence, the radio may automatically change frequency channels or perform vehicle tracking. In a current implementation, the FNE controls geo-fencing operations, wherein each radio periodically reports its location coordinates obtained from, for example, a global positioning satellite (GPS) and/or via a triangulation process to the FNE. The FNE determines a geo-fence boundary, determines, using a radio's location coordinates, when the radio crosses the geo-fence boundary and informs the radio that the radio has crossed the geo-fence boundary for the radio to perform operations associated with entering or exiting the geo-fence.
In another implementation, geo-fencing operations are controlled by the radio, wherein the FNE sends a geo-fence boundary to each radio and each radio tracks its current location and determines if it has crossed the geo-fence boundary. Both of these implementations increase the traffic between the FNE and radios because the radios have to periodically send their GPS coordinates to the FNE or the FNE needs to transmit the coordinates for a complete geo-fence boundary to all radios when a geo-fence is created or changed. The increased traffic between the FNE and the radios requires more frequencies and channels.
A virtual boundary may be of any shape, making the coordinates of a complicated geo-fence (for example, an irregular shaped geo-fence) difficult to accurately define. When the geo-fence is difficult to accurately define, the FNE may or may not transmit the correct geo-fence coordinates to the radios, for example, in the implementation where the radios control the geo-fencing operations.
Accordingly, there is a need for an improved apparatus and method for identifying radio locations relative to a geo-fence.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.